Binance Chain CLI has a sub-command named keys to manage private keys. It is a key store to manage keys for users.

You can add a new key or import a key from seed. Then you can list the keys added and show the detail info of a
specific key. You can also delete the given key or update the password used to protect private key.

Binance Chain CLI use the keys you add to sign transactions for you. For example, if you want to transfer tokens to
someone else, you just need to specify the name of the key you want to use, and input the password of the key, then
Binance Chain CLI will sign the transaction for you if the password is right.

$ ./bnbcli keys
Keys allows you to manage your local keystore for tendermint.
These keys may be in any format supported by go-crypto and can be
used by light-clients, full nodes, or any other application that
needs to sign with a private key.
Usage:
bnbcli keys [command]
Available Commands:
mnemonic Compute the bip39 mnemonic for some input entropy
add Create a new key, or import from seed
list List all keys
show Show key info for the given name
delete Delete the given key
update Change the password used to protect private key
Flags:
-h, --help help for keys
Global Flags:
-e, --encoding string Binary encoding (hex|b64|btc) (default "hex")
--home string directory for config and data (default "/Users/yourname/.bnbcli")
-o, --output string Output format (text|json) (default "text")
--trace print out full stack trace on errors
Use "bnbcli keys [command] --help" for more information about a command.